Long March 7

Long March 7 Y6 transporting to launch site
Function	Medium toheavy-lift launch vehicle
Manufacturer	China Academy of Launch Vehicle Technology
Country of origin	China
Size
Height	7: 53.1 m (174 ft 3 in) 7A: 60.13 m (197 ft 3 in)[1]
Diameter	3.35 m (11 ft)
Mass	7: 597,000 kg (1,316,000 lb)[2] 7A: 573,000 kg (1,263,000 lb)[1]
Stages	7: 2 7A: 3[3]
Capacity
Payload toLEO
Altitude	200 km × 400 km (120 mi × 250 mi)
Orbital inclination	42°
Mass	13,500 kg (29,800 lb)
Payload toGTO
Mass	7,000 kg (15,000 lb)[3]
Payload toTLI
Mass	5,000 kg (11,000 lb)
Payload toSSO
Altitude	700 km (430 mi)
Mass	5,500 kg (12,100 lb)
Associated rockets
Family	Long March
Comparable	Atlas V Delta IV Falcon 9 Block 5 LVM3 H-IIA
Launch history
Status	Active
Launch sites	Wenchang, LC-2
Total launches	22 (7: 10,7A: 12)
Success(es)	21 (7: 10,7A: 11)
Failure	1 (7: 0,7A: 1)
First flight	7: 25 June 2016 7A: 16 March 2020
Last flight	7: 14 July 2025(most recent) 7A: 3 November 2025(most recent)
Boosters – K2
No. boosters	4
Height	27 m (89 ft)
Diameter	2.25 m (7 ft 5 in)
Powered by	1 ×YF-100
Maximum thrust	SL: 1,200 kN (270,000 lbf) vac: 1,340 kN (300,000 lbf)
Total thrust	SL: 4,800 kN (1,100,000 lbf) vac: 5,360 kN (1,200,000 lbf)
Specific impulse	SL: 300 s (2.9 km/s) vac: 335 s (3.29 km/s)
Propellant	RP-1 /LOX
First stage – K3
Diameter	3.35 m (11.0 ft)
Powered by	2 ×YF-100
Maximum thrust	SL: 2,400 kN (540,000 lbf) vac: 2,680 kN (600,000 lbf)
Specific impulse	SL: 300 s (2.9 km/s) vac: 335 s (3.29 km/s)
Propellant	RP-1 /LOX
Second stage
Diameter	3.35 m (11.0 ft)
Powered by	4 ×YF-115
Maximum thrust	706 kN (159,000 lbf)
Specific impulse	342 s (3.35 km/s)
Propellant	RP-1 /LOX
Third stage (CZ-7A)
Diameter	3.0 m (9.8 ft)
Empty mass	2,800 kg (6,200 lb)
Gross mass	21,000 kg (46,000 lb)
Propellant mass	18,200 kg (40,100 lb)
Powered by	2 ×YF-75
Maximum thrust	167.17 kN (37,580 lbf)
Specific impulse	4,295 m/s (438.0 s)
Burn time	478 seconds
Propellant	LH2 /LOX
Fourth stage (optional) –YZ-1A
Powered by	1 ×YF-50D
Maximum thrust	6.5 kN (1,500 lbf)
Specific impulse	315.5 s (3.094 km/s)
Propellant	N2O4 /UDMH
[edit on Wikidata]

TheLong March 7 (Chinese:长征七号运载火箭), orChang Zheng 7 inpinyin, abbreviatedLM-7 for export orCZ-7 within China, originallyLong March 2F/H orChang Zheng 2F/H, nicknamedBingjian (冰箭; 'the Ice Arrow'), is a Chineseliquid-fuelledlaunch vehicle of theLong March family, developed by theChina Aerospace Science and Technology Corporation (CAST).^[4] It made its inaugural flight on 25 June 2016.

Designed as a replacement of theLong March 2F, Long March 7 and its variants was expected to be the workhorse of the fleet, projected to account for around 70% of all Chinese launches. Long March 7 plays a critical role in theChinese Space Station program: it is used to launch theTianzhou robotic cargo and resupply spacecraft to the station. The rocket was intended to replace theLong March 2F as China's crew-rated launch vehicle in the future,^[4] although by 2023 this role has apparently been taken over by the under-developmentLong March 10 and Long March 10A.

Since 2020, in addition to the base Long March 7 configuration, there is theLong March 7A (CZ-7A etc.) variant which differs from the base CZ-7 by the addition of aliquid hydrogen-liquid oxygen third stage inherited from the third stage of theLong March 3B.^[3] The rocket has also been developed into theLong March 8 (using fewer boosters).

The Long March 7 project started in 2008 with the formation of the development team within the traditional designer of space launch vehicles,CALT.^[5] With the acquisition of theRD-120 technology and development of theYF-100 andYF-115 engines, the original plan was to re-engine theLong March 2F. TheLong March 2F/H, as it would have been called, would "just" switch fromN₂O₄ /UDMH to aLOX /kerosene propellant and improved thrust engines to offer better performance. But the switch resulted in a cascade of changes that increased the project complexity significantly.^[6]

At the same time, the originalLong March 5 project was expected to include heavy, medium and light versions. Since the Long March 2F/H and the medium Long March 5 had significant overlaps, it was decided to merge both projects. This way, the high reliability and flight legacy components and technologies of the Long March 2F were merged with the new technologies developed for the Long March 5.^[6] Although finished nearly at the same time, the Long March 6 was a completely separate product developed by a young team withinSAST. As such, it shares little more than tank diameters and propulsion with the LM-5 and LM7, but does cover the range of payloads between the medium Long March 7 and the very lightLong March 11.^[7]

In 2010, the project name was changed officially toLong March 7. According to the project deputy manager, Zhang Tao, the project required eleven new major technologies. But the innovation was not only at the product level, but one at the process itself. This was, according to the project manager, Wang Xiaojun, the first time the whole process was developed in digital 3D, usingcomputer-aided design directly tocomputer-aided manufacturing.^[8]

The inaugural flight was successfully performed on 25 June 2016, at 12:00UTC from theWenchang, LC-2 launch pad. It launched in theLM-7 configuration with the addition of the simultaneously debutingYuanzheng-1A upper stage; the flight performed its multi-orbit mission successfully.^[9]

The Long March 7 is the medium-lift variant of a new generation rocket family that includes the heavier-liftLong March 5 and the small-mid cargoLong March 6. The structure is based on the reliable,human-ratedLong March 2F launch vehicle. It inherited the 3.35 m-diameter core stage and 2.25 m-diameterliquid rocket boosters, but with new engines. Where the earlierLong March 2 rocket family used expensive and dangerousN₂O₄ /UDMH propellants, the Long March 7 usesLOX andkerosene. The engines are shared with the Long March 5 and 6. The goal was to build a more cost-effective and less hazardous rocket family to replace today's Long March 2 and eventually the Long March 3.^[10] It is capable of placing a 5,500 kg (12,100 lb) payload into aSun-synchronous orbit (SSO) of 700 km (430 mi).^[11]

The Long March 7 inherits the modular stages of the originalLong March 5 project. As such, its first stage is the same module as the LM-5 boosters. It also shares tank diameters and engines with theLong March 6, but the design groups were completely different. The LM-5 and LM-7 were developed byChina Academy of Launch Vehicle Technology (CALT), while the LM-6 was done byShanghai Academy of Spaceflight Technology (SAST). Even the avionics are different.^[7]

The basic Long March 7 can be optimized by varying the number of boosters or enhanced by the addition of upper stages. These stages allow more mission flexibility, like direct injection to higher orbits or multiple orbit deployment. They can also increase the performance significantly. Thanks to this modularity, performance can be dialed between 4,000 kg (8,800 lb) and 13,500 kg (29,800 lb) forLEO, 2,000 kg (4,400 lb) and 8,000 kg (18,000 lb) forSSO and 4,000 kg (8,800 lb) and 7,000 kg (15,000 lb) toGeostationary transfer orbit (GTO).^[12][13]

The Long March 7 can use 0, 2 or 4 boosters usingRP-1 /LOXpropellant.^[14] They are powered by a single oxidizer-richstaged combustionYF-100 engine. Each boosters supplies 1,200 kN (270,000 lb_f) at sea level and 1,340 kN (300,000 lb_f) in vacuum of thrust. Itsspecific impulse is 300 s (2.9 km/s) at sea level and 335 s (3.29 km/s) in vacuum. Each module has its own single axisthrust vector control, and thus it required a special design in the control systems of the rocket to coordinate all the rocket's nozzles.^[11][14] They use the legacy 2.25 m (7 ft 5 in) width of theLong March 2 andLong March 3 families, but due to the increased thrust of theYF-100 with respect to theYF-20 andYF-25, the boosters are almost twice as long, at 27 m (89 ft).^[14]

Re-entry of a Long March 7 rocket booster created a fireball visible from portions ofUtah,Nevada,Colorado,Idaho andCalifornia on the evening of 27 July 2016; its disintegration was widely reported onsocial media, and the uncontrolled re-entry of such a five-ton object was regarded as a rare event.^[15]

The first stage has 3.35 m (11.0 ft) diameter tanks carrying RP-1/LOX propellant. It is powered by two YF-100 engines, sharing the same propulsion elements as the boosters, only that for the first stage the engines can gimbal in two axes.^[14] Also, this first stage is the same basic module as theLong March 5 boosters. The diameter was designed for land transport and as such, it will be able to launch from all the Chinese launch sites. This is a critical difference to the LM-5 that requires water transport for its 5 m (16 ft) diameter core stages.^[11] While it shares diameter and engines with theLong March 6 first stage, the development was completely separated and done by different groups.^[7]

The second stage also shares the first 3.35 m (11.0 ft) diameter tanks and propellant. It is powered by four oxidizer-rich staged combustion RP-1/LOXYF-115 engines. Two are fixed and two can gimbal in two axis.^[14] It offers 706 kN (159,000 lb_f) of thrust in vacuum with a specific impulse of 341.5 s (3.349 km/s).^[11] While it shares engines with the Long March 6 second stage, the development were completely separated and done by different groups.^[7]

It can use theYuanzheng-1A upper stage to increase payload to higher energy orbits and enable multiple ignition missions. Particularly, allows direct injection toSSO orbits.^[16] The inaugural flight successfully used this upper stage to deliver multiple payloads to different orbits.^[12]

The Long March 7 is expected to be enhanced by a high-energyliquid hydrogen andliquid oxygen stage. This stage and the low inclination of Wenchang would enable to launch payload between 4,000 kg (8,800 lb) and 7,000 kg (15,000 lb) toGeostationary transfer orbit (GTO) orbit. That would be a 25% increase with respect to the previously most powerful Chinese launcher, theLong March 3B, but well below theLong March 5.^[12] The Long March 7A variant, active since March 2020, accomplishes just this enhancement; it is made of the initial two stages of Long March 7, with a third stage powered by liquid hydrogen and liquid oxygen.

In the 2013 presentation of variations, a hydrogen-powered stage was also used as a second stage. It was not clear if it would be the same stage used as the second stage or a different stage. In both cases (second and third stage) they would be powered by theYF-75 or theYF-75D.^[14]

The 2013 presentation of the variation also proposed smaller 2 m (6 ft 7 in) diameter solid boosters as a cheaper option for smaller payloads.^[14]

After the inaugural flight, Song Zhengyu, Deputy Chief Control Systems Designer for the Long March 7 project, stated that the flight had proven indigenousavionics. They had to work with the local industry to developspace rateddual processorPLCs. It was also stated that thereal-time operating system was also an indigenous development. The general design was based on adistributed architecture to enablescalability andfault tolerance. This avionics would be the base for most future developments and had been designed withreusability in mind.^[17]

In a paper published on theManned Spaceflight publication of theCMSEO, the Long March 7 was presented as a family of launch vehicles.^[14] The variations would be codified by a two number plus variable letters code, and a CZ-7 prefix in the formCZ-7##. The first digit would mean the number of stages in the core, which could be either2 or3. The second number would mean the number of boosters, which could be0,2 or4, with anS appended if the boosters were of solid type. There was also proposed an alternative second stage powered by theLH/LOX propellant and dualYF-75 engines would be identified by appending an(HO) to the designation. At last, it could have an additional upper stage, later identified as theYuanzheng-1A, that would be identified by appending to the designation/SM.^[14]

For example, the version that debuted was codified under this nomenclature as theCZ-724/SM, since it had twoRP-1/LOX core stages, four liquid boosters and was enhanced by the Yuanzheng-1A stage. ACZ-720 would have two RP-1/LOX stages and no boosters. ACZ-724S(HO) would have a RP-1/LOX first stage, a LH/LOX second stage and four solid boosters. ACZ-732 would have two RP-1/LOX stages, a LH/LOX third stage, and two liquid boosters. The paper expected the following performance from certain versions.^[14]

The paper also presented the propulsion options for each stage. TheRP-1/LOX second stage had only twoYF-115 instead of the normal four, when used in the version with no boosters. It might have implied a different smaller upper stage or an under filled one.^[14]

Since 2020, the base two-stage CZ-7 configuration has been supplemented by the CZ-7A variant. This variant employs the boosters and the first two stages of the base configuration, and add to this a third stage that employs two cryogenicYF-75 engines operating onLH₂ andLOX liquid fuels; the third stage of the 7A variant is inherited from the third stage of theLong March 3B. (Note that the 7A variant is similar to the CZ-73X variants first proposed in 2013; see previous subsection).

The maiden CZ-7A was launched on 16 March 2020 at 13:34 UTC from Wenchang Satellite Launch Center on Hainan island. Two hours after launch, state news sources announced that the flight ended in failure; no causes for the failure were indicated initially. Launch preparations for the maiden flight continued in the weeks prior to launch despite measures taken to combat the spread of the COVID-19 virus in China.^[18] In 2021, some observers speculated, based on unconfirmed ChineseBaidu posts, that the failure of the CZ-7A's maiden flight was caused by the loss of pressurization in one of its four boosters just prior tomain engine cutoff and thestaging of the first stage (about 168 seconds into the flight).^[19]

The second CZ-7A launched successfully from Wenchang on 11 March 2021.^[20] The launch vehicle carried theShiyan-9 satellite to test new technologies such as space environmental monitoring, according to theChina Aerospace Science and Technology Corporation (CASC).^[21]

Launch outcomes :

• List of Long March launches (2025-2029)

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